From bc0de86b495ae014b209431ed7cb90fc3d5e4d1f Mon Sep 17 00:00:00 2001 From: Kir Kolyshkin Date: Mon, 9 Apr 2018 15:58:40 -0700 Subject: [PATCH] archive/tar: do not populate user/group names This reverts part of commit 29a18899379c ("archive/tar: populate uname/gname/devmajor/devminor in FileInfoHeader"). The reason is using os/user functions to resolved uids/gids to names breaks the static build for Linux/glibc case (the resulting binary panics on NULL pointer dereference). For much more details, see https://github.com/golang/go/issues/23265 Signed-off-by: Kir Kolyshkin --- src/archive/tar/stat_unix.go | 26 +++----------------------- 1 file changed, 3 insertions(+), 23 deletions(-) diff --git a/src/archive/tar/stat_unix.go b/src/archive/tar/stat_unix.go index 868105f338..9640ed4bab 100644 --- a/src/archive/tar/stat_unix.go +++ b/src/archive/tar/stat_unix.go @@ -8,10 +8,7 @@ package tar import ( "io/fs" - "os/user" "runtime" - "strconv" - "sync" "syscall" ) @@ -19,10 +16,6 @@ func init() { sysStat = statUnix } -// userMap and groupMap caches UID and GID lookups for performance reasons. -// The downside is that renaming uname or gname by the OS never takes effect. -var userMap, groupMap sync.Map // map[int]string - func statUnix(fi fs.FileInfo, h *Header) error { sys, ok := fi.Sys().(*syscall.Stat_t) if !ok { @@ -31,22 +24,9 @@ func statUnix(fi os.FileInfo, h *Header) error { h.Uid = int(sys.Uid) h.Gid = int(sys.Gid) - // Best effort at populating Uname and Gname. - // The os/user functions may fail for any number of reasons - // (not implemented on that platform, cgo not enabled, etc). - if u, ok := userMap.Load(h.Uid); ok { - h.Uname = u.(string) - } else if u, err := user.LookupId(strconv.Itoa(h.Uid)); err == nil { - h.Uname = u.Username - userMap.Store(h.Uid, h.Uname) - } - if g, ok := groupMap.Load(h.Gid); ok { - h.Gname = g.(string) - } else if g, err := user.LookupGroupId(strconv.Itoa(h.Gid)); err == nil { - h.Gname = g.Name - groupMap.Store(h.Gid, h.Gname) - } - + // TODO(bradfitz): populate username & group. os/user + // doesn't cache LookupId lookups, and lacks group + // lookup functions. h.AccessTime = statAtime(sys) h.ChangeTime = statCtime(sys) base-commit: 4af1337d1e9eb9e7b766c9deb787c78413bb25c4 -- 2.24.1